Just completed (2) 6' X 10' x 6' tall grow out cages. Nothing fancy or pretty and just used material I had lying around. Probably one for males and one for females is going to be the strategy with a mature male in the pen with the young males to break up any arguments amongst the young ones. Here are a couple photos. Three foot up solid walls should be enough to keep the pitbulls out.

TRy it and you need to go higher just add to it. Small compartment are tough to prevent this in. They scratch and it flys all over. If your compartments are large enough you can set it on a piece of plywood. That gives more surface area for the shavings can pile up on before reaching the feed trough. Then just brush it of daily.